text: // Copyright 2010 the V8 project authors. All rights reserved.
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  //       notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  //       copyright notice, this list of conditions and the following
  //       disclaimer in the documentation and/or other materials provided
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  // Test the ToPrimitive internal function used by ToNumber/ToString.
  // Does it [[Get]] and [[Call]] the object's toString and valueOf properties
  // correctly. Specifically, does it call [[Get]] only once per property.
  
  var o1 = { toString: function() { return 42; },
             valueOf: function() { return "37"; } };
  var n1 = Number(o1);
  var s1 = String(o1);
  assertTrue(typeof n1 == "number");
  assertTrue(typeof s1 == "string");
  
  var trace = [];
  var valueOfValue = 42;
  var toStringValue = "foo";
  function traceValueOf () {
    trace.push("vo");
    return valueOfValue;
  };
  function traceToString() {
    trace.push("ts");
    return toStringValue;
  };
  var valueOfFunc = traceValueOf;
  var toStringFunc = traceToString;
  
  var ot = { get toString() { trace.push("gts");
                              return toStringFunc; },
             get valueOf() { trace.push("gvo");
                             return valueOfFunc; }
  };
  
  var nt = Number(ot);
  assertEquals(42, nt);
  assertEquals(["gvo","vo"], trace);
  
  trace = [];
  var st = String(ot);
  assertEquals("foo", st);
  assertEquals(["gts","ts"], trace);
  
  trace = [];
  valueOfValue = ["not primitive"];
  var nt = Number(ot);
  assertEquals(Number("foo"), nt);
  assertEquals(["gvo", "vo", "gts", "ts"], trace);
  
  trace = [];
  valueOfValue = 42;
  toStringValue = ["not primitive"];
  var st = String(ot);
  assertEquals(String(42), st);
  assertEquals(["gts", "ts", "gvo", "vo"], trace);
  
  trace = [];
  valueOfValue = ["not primitive"];
  assertThrows("Number(ot)", TypeError);
  assertEquals(["gvo", "vo", "gts", "ts"], trace);
  
  
  toStringFunc = "not callable";
  trace = [];
  valueOfValue = 42;
  var st = String(ot);
  assertEquals(String(42), st);
  assertEquals(["gts", "gvo", "vo"], trace);
  
  valueOfFunc = "not callable";
  trace = [];
  assertThrows("String(ot)", TypeError);
  assertEquals(["gts", "gvo"], trace);
  
  toStringFunc = traceToString;
  toStringValue = "87";
  trace = [];
  var nt = Number(ot);
  assertEquals(87, nt);
  assertEquals(["gvo", "gts", "ts"], trace);
  